<!DOCTYPE html>
<html>
  <head>
    <title>Stretchy mover</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
  </head>
  <body>
    <!-- See bug 687807 -->
    <math>
      <mover>
        <mo stretchy="true">&Vert;</mo>
        <mn>BBBBBBBBB</mn>
      </mover>
    </math>
  </body>
</html>
